Exchange troubled cell

Some more features for LimitPass.

dune/fem-dg/operator/dg/operatortraits.hh

@@ -60,19 +60,31 @@ namespace Fem
     static_assert( std::is_same<typename ModelType::RangeType, typename DestinationType::RangeType>::value, "range type does not fit.");
 
     // default quadrature selection should be CachingQuadrature
-    template <class Grid, bool useCaching>
+    template <class Grid, bool cachingStorage, bool regularGrid>
     struct SelectQuadrature
     {
       typedef Fem::CachingQuadrature< GridPartType, 0, QuadratureTraits >  VolumeQuadratureType;
       typedef Fem::CachingQuadrature< GridPartType, 1, QuadratureTraits >  FaceQuadratureType;
     };
 
+    // if selected discrete function space has caching storage,
+    // but the grid is polygonal or polyhedral in 2d we can use
+    // CachingQuadarature for face integrals (edges in 2d)
+    template <class Grid>
+    struct SelectQuadrature< Grid, true, false >
+    {
+      typedef Fem::ElementQuadrature< GridPartType, 0, QuadratureTraits >  VolumeQuadratureType;
+      typedef typename std::conditional< GridType::dimension < 3,
+                        Fem::CachingQuadrature< GridPartType, 1, QuadratureTraits >,
+                        Fem::ElementQuadrature< GridPartType, 1, QuadratureTraits > > ::type   FaceQuadratureType;
+    };
+
     // if selected discrete function space has no caching storage,
     // then select ElementQuadrature, and not  CachingQuadrature
     // also, if the grid is polygonal or polyhedral
     // CachingQuadarature cannot be used
     template <class Grid>
-    struct SelectQuadrature< Grid, false >
+    struct SelectQuadrature< Grid, false, false >
     {
       typedef Fem::ElementQuadrature< GridPartType, 0, QuadratureTraits >  VolumeQuadratureType;
       typedef Fem::ElementQuadrature< GridPartType, 1, QuadratureTraits >  FaceQuadratureType;
@@ -105,10 +117,10 @@ namespace Fem
       static const bool value = false;
     };
 
-    static const bool useCaching = CheckSpace< DiscreteFunctionSpaceType > :: value &&
-                                   CheckGrid < GridType > :: value;
-
-    typedef SelectQuadrature< GridType, useCaching >  SelectQuadratureType;
+    // define quad selector which contains the correct types for quadratures
+    typedef SelectQuadrature< GridType,
+                              CheckSpace< DiscreteFunctionSpaceType > :: value,
+                              CheckGrid < GridType > :: value >  SelectQuadratureType;
 
     typedef typename SelectQuadratureType::VolumeQuadratureType   VolumeQuadratureType;
     typedef typename SelectQuadratureType::FaceQuadratureType     FaceQuadratureType;